Kitchen gardening: an A to Z

A is for allotments; B is for brocolli; C is for climate change... and U is for urine. 'The Alternative Kitchen Garden: an A-Z' is a companion for both inexperienced and expert gardeners

Growing your own food is not just about sustainability; it is a state of mind. As anyone who grows their own veg knows, you only have to start simple and before you know it you're hooked.

If you don't know where to start, The Alternative Kitchen Garden: an A-Z shows that there isn't really a start, just an experiment. And if you have been experimenting, this book will take you a step further.

Through trial and error, writer, photographer and keen gardener Emma Cooper brought her garden from an unloved tangle of brambles to an experimental kitchen garden - hooked from the first harvest.

The book is an extension of Emma Cooper's blog site, pulling together eight years of her postings and stories. In this sense it gives a friendly and personal account of her knowledge and experiences, occasionally rambling into the unexpected. As an A-Z it is easy to dip in and out of, and covers a surprising range of topics.

Not only will you find practical advice on growing your veggies, but it will help you understand your plants and their nutrients - U is for Urine and X is for Xylem - and you will learn a thing or two about the birds and the bees as well.

As with any blog, also there are also a few informative diversions helping you get involved; T is for Thrive, a UK charity running horticultural therapy gardens, and M is for Master Composters, volunteers who solve people's composting problems.

Review by Alex McDonald

Below are some edited extracts from the book:

I is for... Intercropping

Intercropping, undercropping, catch cropping and double cropping are all slightly different ways of doing the same thing - growing more than one crop in the same space and thereby increasing harvests.

Intercropping is using the space between plants that will eventually become large, like brassicas or squash. While the main crop is small, fast-growing plants like lettuce or radishes are sown in the spaces between. By the time the larger crop grows into the space, the intercrop will have been harvested and eaten.

Undercropping relies on the fact that some plants like a bit of shade. Growing shade-loving crops (like lettuce) underneath taller plants gives them a little bit of shade, and acts as a living mulch for the taller plants.

Catch cropping fills the gap between harvesting one crop and planting the next. If you've got a little patch of ground that isn't due to be used for a couple of weeks then you've got enough time to grow radishes, lettuce and salad or some of the fast-growing Oriental vegetables. When it's time to sow or plant out the next main crop, you'll have young and tasty salad vegetables to harvest.

Double cropping involves growing two vegetables in exactly the same place, and relies on different growth rates. The classic example is that of sowing radish and parsnips in the same rows. Parsnips are notoriously slow to germinate, and the radishes will quickly sprout and mark the rows - making weeding in between a doddle. Once the parsnips make an appearance, it will be time to harvest the radishes and the parsnips can have the space to themselves.

Intercropping is a great way to prevent monocultures and the pest and disease problems they encourage. You could even try planting two different varieties of the same crop (with different disease resistance) together. But the golden rule with all of these techniques is to avoid a situation where growing a second crop interferes with the main crop. If you try and cram too much into the space you'll be making problems for yourself, increasing the need to water and cutting down on the air flow between plants that is essential to prevent fungal diseases.

K is for.... K (Potassium)

There are three major plant nutrients (also sometimes called macronutrients) - referred to on fertiliser packets as N, P and K. N is for nitrogen, P for phosphorus and K for potassium (also known to gardeners as potash).

Potassium encourages fruiting and flowering in plants. Liquid feeds for tomatoes (and peppers and aubergines) are high in potassium. Potassium also promotes healthy growth, toughening plants up and increasing their ability to cope with stresses like drought in the summer and cold weather in the winter.

The main problem with potassium is that it tends to form water-soluble compounds, meaning that it can easily be leached out of soil (particularly sandy soils) in wet weather.

Comfrey is a great source of potassium-rich fertiliser, and you can turn comfrey into a liquid feed for your tomatoes and peppers or use it to pep up your home-made compost. Other readily available sources include banana skins and wood ash, which was used by gardeners during WWII when fertilisers were in short supply.

O is for... Oca

One of the joys of globalisation is that your garden can become a smorgasbord of plants from all over the world. You can have a bed of Oriental vegetables next to one filled with the Lost Crops of the Incas and no one will bat an eyelid. In fact we're all doing it anyway - potatoes, tomatoes, peppers and aubergines all hail from South America, sunflowers and Jerusalem artichokes have travelled from North America and beetroot, radishes and cabbage were domesticated in the Mediterranean region.

I can really see Oca catching on with kitchen gardeners in temperate zones. For a start, the tubers are beautiful. They come in a rainbow of colours. I'm growing two - pearly white and brilliant red. They're knobbly tubers, like Chinese artichokes, and they need a long season to grow. The tubers don't start to form until after the summer solstice, so if you can protect them from early autumn frosts you stand a better chance of a decent harvest. They're supposed to be like lemony potatoes, but I can neither confirm nor deny that until later this year!

What I can say is that the plants have lovely and unusual foliage. They have divided leaves, a bit like four-leaved clover, held on thick stems - the growth pattern is (not surprisingly, perhaps) a bit reminiscent of potatoes. They seem to be fairly resilient, although the leaves tend to curl in on themselves a bit when the weather is hot. The only pest problem I've had is with blackfly - but they've been infesting everything this year.

My oca are all growing in containers, so (like other tubers) I may get limited yields, but the tubers store very well so once you have oca you can save your own tubers and replant them each year without having to buy new seed.

P is for... pH (soil)

As you might remember from your school days, pH is a measurement of the acidity of something. The pH of your garden soil depends on the underlying rocks and geography - and there's not much you can do to change it because there's so much of it. However, you can adapt your planting to your conditions, and manage the pH in small areas of the garden.

The problem lies in the fact that the pH of your soil affects the soil chemistry and hence the availability of nutrients for your plants. At extremes of the pH scale (and it runs from 1 (very acid) to 14 (very alkaline)), different nutrients will be almost completely unavailable to plants; they have adapted to these growing conditions - and won't thrive at different pH levels as a result.

Most garden vegetables like a soil that's roughly in the middle - between about 6 and 8 - and 7 is a neutral soil that is neither acidic nor alkaline. You can measure the pH of your soil using either a meter with a metal probe, or a little chemistry set. It's possible that the pH of the soil varies in different places in your garden, so it's worth taking a series of measurements to see what's what.

Plants that like alkaline soil are known as 'lime-loving' or calcicole plants. They include brassicas. Plants that like acid soil are known as 'lime-hating' or calcifuge. Blueberries are a prime example - you can only grow them in acid soil.

If you follow a traditional crop rotation then you will be applying lime (a source of calcium) to one of your beds each year. Lime is also used to balance the pH of compost heaps and to help manage heavy soils. Since I have a very alkaline soil it's not something I've ever had to do.Whatever type of soil you have, adding organic matter can help to keep a plentiful supply of nutrients available for plants.

The Alternative Kitchen Garden: an A-Z (£14.95, Permanent Publications) is out now

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